Seven reasons why a global pandemic is inevitable

Updated 8:18 AM ET, Mon April 3, 2017

Chat with us in Facebook Messenger. Find out what's happening in the world as it unfolds.

Photos:Seven reasons why a global pandemic is inevitable

Growing populations and urbanization – The globe's growing population creates greater opportunity for diseaseto spread through air, mosquitoes or unclean water, particularly in urban areas. The United Nations predicts that 66% of the global population will live in urban areas by 2050.

Hide Caption

1 of 7

Photos:Seven reasons why a global pandemic is inevitable

Encroaching into new environments – As humans expand into previously uninhabited territories such as forests, they are more likely to come into more frequent contact with wild animals and, inevitably, new infections.

Hide Caption

2 of 7

Photos:Seven reasons why a global pandemic is inevitable

Climate change – Evidence suggests climate change is causing greater numbers of heat waves and flooding events, bringing more opportunity for waterborne diseases such as cholera and for diseases carried by mosquitoes.

Hide Caption

3 of 7

Photos:Seven reasons why a global pandemic is inevitable

Global travel – According to experts, infectious agents can live in humans during their incubation period -- the time between infection and the onset of symptoms -- meaning that travelers can transmit an infection to another region even though they don't appear to be sick. International tourist arrivals reached a record of almost 1.2 billion in 2015.

Hide Caption

4 of 7

Photos:Seven reasons why a global pandemic is inevitable

Civil conflict – If a country is on the brink of breakdown from civil unrest, its ability to handle an intense and sudden outbreak could bring its people to their knees -- and allow the infection to flourish.

Hide Caption

5 of 7

Photos:Seven reasons why a global pandemic is inevitable

Faster spread of information – In the information age, new means of communication bring higher levels of fear and multiple ways to spread it, experts believe. More than 90% of the world's population will be covered by mobile broadband networks by 2021, according to the UN.

Hide Caption

6 of 7

Photos:Seven reasons why a global pandemic is inevitable

Fewer doctors and nurses in outbreak regions – Countries where outbreaks are more likely to occur also have fewer doctors and nurses to treat the population. Most have left for better prospects elsewhere. Here a nurse administers a yellow fever vaccine in Rio de Janeiro, Brazil.

Hide Caption

7 of 7

As we live closer together and push global boundaries, experts believe we need to be more prepared for the next infection that may become a pandemic.